The long term objectives of this application are twofold: to provide a clear understanding of the physical mechanisms governing the increases in detection sensitivity demonstrated to date by the proposed methodology and to construct and test prototype hardware from which commercial high mass detection instrumentation can be designed and manufactured. The specific aim of Phase II research is to continue exploring the promising new technology for detecting high mass ions which does not depend exclusively on kinetic ejection of secondary electrons and does not use excessively high voltages for operation. The mechanisms responsible for improving the yield of negative secondary particles at the ion impact dynode will be examined through careful alteration of the dynode surface. The types of the secondary particles will be determined by first measuring the ratio of secondary electrons to secondary ions at high and low work function surfaces. The nature of the secondary ions will also be determined by a series of MS/MS measurements. Of concern are the means of changing the work function and the long term stability effects. Both coating and target substrate materials will be studied. Finally, based upon the information obtained during the course of the program, prototype detectors will be constructed and tested on at least three different mass spectrometers.